Elected magnet



(No Model.)

F. A. LANE.

ELECTED MAGNET.

No. 393,337. Patented Nov. 20, 1888.

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N. PETERS, PhotwLithographen Washmgtou. no.

UNITED STATES PATENT Oriana.

FREDERTC A. LANE, OF NEW HAVEN, CONNECTICUT, ASSIGNOl-t OF ONE-HALF TO FRANK E. MORGAN, OF SAME PLACE.

MAGNET.

SPBCIFICATION forming part of Letters Patent No. 393,337, dated November 20, 1888.

Application filed January 30. 1888. Serial Nofifiliflli. (No model.)

T all whom it may concern:

Be it known that I, Fennnnrc A. LANE, of New Haven, in the county of New Haven and State of Connecticut, have invented a new Improvement in Electro-Magnets; and I do hereby declare the following, when taken in connection Vii-11 accompanying drawings and the letters of reference marked thereon, to be a full, clear, and exact description of the same, and

which said drawings constitute part of this specification, and represent, in-

Figure 1, a perspective view of the magnet complete, looking toward the contact or working face of the core; Fig. 2, a perspective view 15 of the tubular core as prepared to receive the heads; Fig. 3, a vertical central section through the core with the heads set in place; Fig. 4;, the same as Fig. 3, with the ends of the tube closed down upon the heads to secure themin place; Fi 5, a vertical central section of the magnet with the securing-pin introduced,and showing a tube within the tubular core; Fig. 6, a side view of the best construction of the inner tube; Fig. 7, a modification in the con 2 struction of the tubular core.

This invention relates to an improvement in elcctro-magnets.

In the more general construction of this class of magnets the core upon which the wire is 0 wound has been made from solid soft iron, one end of the solid core forming the active face. I have discovered that by increasing the surface of the core the power of the magnet is correspondinglyincreased, or substantially so;

but with a solid core this surface cannot be increased without increasing the size of the magnet.

The object of my invention is to increase the surface of the core without nccessarilyincreas- 4o ing the size of the magnet.

To that end my invention consists of a magnet composed of a tubular metal core, wirewound upon said core, and said tubular core closed at one end to form the active or contact 5 surface of the magnet, and as more-fully hereinafter described.

In carrying out my invention I find a very good result by making the tubular core from fine sheet tin, such tin being usually made from the finest soft Norway iron. From a piece of sheet-lin of the required size I form nular bead, a. Onto each end of the tube A the heads 13 C are placed, the extreme ends of the tube projecting slightly through the respective heads, the heads resting against the annular beads a, as seen in Fig. 3. Then t projecting ends of the tube are struck dm 1 upon the outer surface of the heads, so :5: i clamp the heads between the beads a on tube and the turned-down outer ends of th. tube, thus securing the heads to the tube. The tube A forms the core for the magnet. The core is then wound in the usual manner, as represented in Fig. 5. Then to secure the magnet a pin, D, of less diameter than theinterior of the core, is introduced through the tubular core, the said pin having a head, E, which laps onto the end of the tubular core, so as to make metallic connection therewith, the said head forming the active or contact face of the magnet, substantially like the usual projecting end of the solid core. This completes the magnet. Under this construe tion the core-surface is substantially doubled over what it would be with the core so1id,and the power of the magnet I find by practical tests to be proportionately increased.

The construction thus far described represents the tubular core in its simplest construction.

To increase the core-surface to a consider 8- ablygreatcr extent, I introduce within the tubular core other tubes-say, as indicated by a tube, F, Fig. 5. This inner tube may be made from tin, in the same manner as the tube A, and several such tubes may be introduced 0 concentrically with each other, each tube increasing the core-surface to a very great on tent. Contact, however, must be made between the cnds of the inner tube and the outer tube or core, A. This is done by the head E at one end and the seat for the magnet at the opposite end; but I find a better construction for the inner tubes to be to make the tube from wire or a flat strip of metal, coiled after the manner of a helical spring, somewhat open,

as indicated in Fig. 6, so as to give them a certain degree of compressibility. Then when introduced into the tubular core A they should be of a somewhat greater length than the said core A, and so that the head or closed end of the core will compress them to some extent, so as to insure positive contact.

I illustrate the helical tube as detached from the core, as a convenience for illustration. It is, however, to be understood as forming a part of the most perfect construction of my improved magnet.

The principal tube may also be made helical, as represented in Fig. 7, and thereby acquire the compressibility which I have described with reference to the inner helical tubes. By the term tube I wish to be understood as includinga core of tubular character in contradistinction to a solid core, irrespective of any particular construction of such tubular core.

I have represented the magnet as constructed with heads B O, in the usual manner for making this class of magnets; but it will be understood that the heads may be omitted in this case, as they are sometimes omitted in the case 'of a solid core. Such omission, however, is a inner or auxiliary tubes, as the single tubular core produces a good result in giving a greatly increased power of magnet over a solid core.

I claim 1. An electro-magnet consisting of a tubular metal core, wire wound upon said core, combined with a pin through said tubular core, but of less diameter than the internal diameter of the core, and constructed with a head projecting from the pin, so as to rest upon theexposed end of said tube, the said head serving to make metallic connection between the said tube and the said pin, substantially as described.

2. An electromagnet consisting of a tubular metal core closed at one end to form the active contact face of the magnet, wire wound upon said core, combined with one or more metal tubes within said tubular core, each of said inner tubes in contact with the closed end of the core, substantially as described.

3. An electro-magnet consisting of a tubular metal core closed atone end to form the acting or contact face of the magnet,wire wound upon said core, one or more metal tubes within said tubular core, the said inner tubes madein the form of helices, so as to be compressible in the direction of their axis, the said inner tubesin contact with the closed end of the tubular core, substantially as described.

FREDERIG A. LANE.

Witnesses:

JOHN E. EARLE, J. H. SHUMWAY. 

